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Aircrew exposure from cosmic radiation on commercial airline routes.

https://arctichealth.org/en/permalink/ahliterature193325
Source
Radiat Prot Dosimetry. 2001;93(4):293-314
Publication Type
Article
Date
2001
Author
B J Lewis
M J McCall
A R Green
L G Bennett
M. Pierre
U J Schrewe
K. O'Brien
E. Felsberger
Author Affiliation
Royal Military College of Canada, P.O. Box 17000, Kingston, Ontario, Canada K7K 7B4. lewis-b@rmc.ca
Source
Radiat Prot Dosimetry. 2001;93(4):293-314
Date
2001
Language
English
Publication Type
Article
Keywords
Aircraft
Altitude
Aviation
Canada
Cosmic Radiation
Humans
Occupational Exposure
Radiation Dosage
Radiometry - instrumentation - methods
Abstract
As a result of the recent recommendations of the ICRP 60, and in anticipation of possible regulation on occupational exposure of Canadian-based aircrew, an extensive study was carried out by the Royal Military College of Canada over a one-year period to measure the cosmic radiation at commercial jet altitudes. A tissue-equivalent proportional counter was used to measure the ambient total dose equivalent rate on 62 flight routes, resulting in over 20,000 data points at one-minute intervals at various altitudes and geomagnetic latitudes (i.e. which span the full cut-off rigidity of the Earth's magnetic field). These data were then compared to similar experimental work at the Physikalisch Technische Bundesanstalt, using a different suite of equipment, to measure separately the low and high linear energy transfer components of the mixed radiation field, and to predictions with the LUIN transport code. All experimental and theoretical results were in excellent agreement. From these data, a semiempirical model was developed to allow for the interpolation of the dose rate for any global position, altitude and date (i.e. heliocentric potential). Through integration of the dose rate function over a great circle flight path, a computer code was developed to provide an estimate of the total dose equivalent on any route worldwide at any period in the solar cycle.
PubMed ID
11548357 View in PubMed
Less detail

Assessment of the cosmic radiation exposure on Canadian-based routes.

https://arctichealth.org/en/permalink/ahliterature196836
Source
Health Phys. 2000 Nov;79(5):568-75
Publication Type
Article
Date
Nov-2000
Author
P. Tume
B J Lewis
L G Bennett
M. Pierre
T. Cousins
B E Hoffarth
T A Jones
J R Brisson
Author Affiliation
Royal Military College of Canada, Kingston, Ontario. tumep@aecl.ca
Source
Health Phys. 2000 Nov;79(5):568-75
Date
Nov-2000
Language
English
Publication Type
Article
Keywords
Aircraft
Calibration
Canada
Cosmic Radiation
Humans
Occupational Exposure
Radiometry
Abstract
As a result of the recent recommendations of the ICRP-60 and in anticipation of possible regulation on occupational exposure of commercial aircrew, a two-phase investigation was carried out over a 1-y period to determine the total dose equivalent on representative Canadian-based flight routes. In the first phase of the study, dedicated scientific flights on a Northern round-trip route between Ottawa and Resolute Bay provided the opportunity to characterize the complex mixed-radiation field and to intercompare various instrumentation using both a conventional suite of powered detectors and passive dosimetry. In the second phase, volunteer aircrew carried (passive) neutron bubble detectors during their routine flight duties. From these measurements, the total dose equivalent was derived for a given route with a knowledge of the neutron fraction as determined from the scientific flights and computer code (CARI-3C) calculations. This study has yielded an extensive database of over 3,100 measurements providing the total dose equivalent for 385 different routes. By folding in flight frequency information and the accumulated flight hours, the annual occupational exposures of 20 flight crew have been determined. This study has indicated that most Canadian-based domestic and international aircrew will exceed the proposed annual ICRP-60 public limit of 1 mSv y(-1) but will be well below the occupational limit of 20 mSv y(-1).
PubMed ID
11045532 View in PubMed
Less detail

Bubble-detector measurements in the Russian segment of the International Space Station during 2009-12.

https://arctichealth.org/en/permalink/ahliterature266545
Source
Radiat Prot Dosimetry. 2015 Jan;163(1):1-13
Publication Type
Article
Date
Jan-2015
Author
M B Smith
S. Khulapko
H R Andrews
V. Arkhangelsky
H. Ing
B J Lewis
R. Machrafi
I. Nikolaev
V. Shurshakov
Source
Radiat Prot Dosimetry. 2015 Jan;163(1):1-13
Date
Jan-2015
Language
English
Publication Type
Article
Keywords
Cosmic Radiation
Humans
Linear Energy Transfer
Neutrons
Phantoms, Imaging
Radiation Dosage
Radiation Monitoring - instrumentation - methods
Radiation Protection
Russia
Space Flight
Spacecraft - instrumentation
Time Factors
Abstract
Measurements using bubble detectors have been performed in order to characterise the neutron dose and energy spectrum in the Russian segment of the International Space Station (ISS). Experiments using bubble dosemeters and a bubble-detector spectrometer, a set of six detectors with different energy thresholds that is used to determine the neutron spectrum, were performed during the ISS-22 (2009) to ISS-33 (2012) missions. The spectrometric measurements are in good agreement with earlier data, exhibiting expected features of the neutron energy spectrum in space. Experiments using a hydrogenous radiation shield show that the neutron dose can be reduced by shielding, with a reduction similar to that determined in earlier measurements using bubble detectors. The bubble-detector data are compared with measurements performed on the ISS using other instruments and are correlated with potential influencing factors such as the ISS altitude and the solar activity. Surprisingly, these influences do not seem to have a strong effect on the neutron dose or energy spectrum inside the ISS.
PubMed ID
24714114 View in PubMed
Less detail

Bubble-detector measurements of neutron radiation in the international space station: ISS-34 to ISS-37.

https://arctichealth.org/en/permalink/ahliterature278704
Source
Radiat Prot Dosimetry. 2016 Feb;168(2):154-66
Publication Type
Article
Date
Feb-2016
Author
M B Smith
S. Khulapko
H R Andrews
V. Arkhangelsky
H. Ing
M R Koslowksy
B J Lewis
R. Machrafi
I. Nikolaev
V. Shurshakov
Source
Radiat Prot Dosimetry. 2016 Feb;168(2):154-66
Date
Feb-2016
Language
English
Publication Type
Article
Keywords
Cosmic Radiation
Equipment Design
Humans
Monte Carlo Method
Neutrons
Phantoms, Imaging
Radiation Dosage
Radiation Monitoring - methods
Russia
Spacecraft
Abstract
Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2. The Radi-N2 dose and spectral measurements are not significantly different from the Radi-N results collected in the same ISS locations, despite the large difference in solar activity between 2009 and 2013. Parallel experiments using a second set of detectors in the Russian segment of the ISS included the first characterisation of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom. These data suggest that the dose inside the phantom is ~70% of the dose at its surface, while the spectrum inside the phantom contains a larger fraction of high-energy neutrons than the spectrum outside the phantom. The phantom results are supported by Monte Carlo simulations that provide good agreement with the empirical data.
PubMed ID
25899609 View in PubMed
Less detail

Characterisation of neutron-sensitive bubble detectors for application in the measurement of jet aircrew exposure to natural background radiation.

https://arctichealth.org/en/permalink/ahliterature193365
Source
Nucl Instrum Methods Phys Res A. 1998;406(1):153-68
Publication Type
Article
Date
1998
Author
P. Tume
B J Lewis
L G Bennett
T. Cousins
Author Affiliation
Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston. tume-p@rmc.ca
Source
Nucl Instrum Methods Phys Res A. 1998;406(1):153-68
Date
1998
Language
English
Publication Type
Article
Keywords
Air Pressure
Aircraft - instrumentation
Calibration
Canada
Dose-Response Relationship, Radiation
Evaluation Studies as Topic
Humans
Mathematics
Military Personnel
Models, Theoretical
Neutrons
Radiation Dosage
Radiation Monitoring - instrumentation
Temperature
Abstract
A survey of the natural background dose equivalent received by Canadian Forces aircrew was conducted using neutron-sensitive bubble detectors (BDs) as the primary detection tool. Since this study was a new application for these detectors, the BD response to neutron dose equivalent (RD) was extended from thermal to 500 MeV in neutron energy. Based upon the extended RD, it was shown that the manufacturer's calibration can be scaled by 1.5 +/- 0.5 to give a BD sensitivity that takes into account recently recommended fluence-to-neutron dose equivalent conversion functions and the cosmogenic neutron spectrum encountered at jet altitudes. An investigation of the effects of systematic bias caused by the cabin environment (i.e., temperature, pressure and relative humidity) on the in-flight measurements was also conducted. Both simulated and actual aircraft climate tests indicated that the detectors are insensitive to the pressure and relative humidity variations encountered during routine jet aircraft operations. Long term conditioning tests also confirmed that the BD-PND model of detector is sensitive to variations in temperature to within +/- 20%. As part of the testing process, the in-flight measurements also demonstrated that the neutron dose equivalent is distributed uniformly throughout a Boeing 707 jet aircraft, indicating that both pilots and flight attendants are exposed to the same neutron field intensity to within experimental uncertainty.
PubMed ID
11542590 View in PubMed
Less detail

Cosmic radiation exposure on Canadian-based commercial airline routes.

https://arctichealth.org/en/permalink/ahliterature193364
Source
Radiat Prot Dosimetry. 1999;86(1):7-24
Publication Type
Article
Date
1999
Author
B J Lewis
P. Tume
L G Bennett
M. Pierre
A R Green
T. Cousins
B E Hoffarth
T A Jones
J R Brisson
Author Affiliation
Royal Military College of Canada, Kingston.
Source
Radiat Prot Dosimetry. 1999;86(1):7-24
Date
1999
Language
English
Publication Type
Article
Keywords
Aerospace Medicine
Aviation - standards
Calibration
Canada
Cosmic Radiation
Databases, Factual
Humans
Linear Energy Transfer
Magnetics
Neutrons
Occupational Exposure
Protons
Radiation Dosage
Radiation monitoring
Radiation Protection - standards
Solar Activity
Abstract
As a result of the recent recommendations of ICRP 60 and in anticipation of possible regulation on occupational exposure of commercial aircrew, a two-part investigation was carried out over a one-year period to determine the total dose equivalent on representative Canadian-based flight routes. As part of the study, a dedicated scientific measurement flight (using both a conventional suite of powered detectors and passive dosimetry) was used to characterise the complex mixed radiation field and to intercompare the various instrumentation. In the other part of the study, volunteer aircrew carried (passive) neutron bubble detectors during their routine flight duties. From these measurements, the total dose equivalent was derived for a given route with a knowledge of the neutron fraction as determined from the scientific flight and computer code (CARI-LF) calculations. This investigation has yielded an extensive database of over 3100 measurements providing the total dose equivalent for 385 different routes. By folding in flight frequency information and the accumulated flight hours, the annual occupational exposures of 26 flight crew have also been determined. This study has indicated that most Canadian-based domestic and international aircrew will exceed the proposed annual ICRP 60 public limit of 1 mSv.y-1, but will he well below the occupational limit of 20 mSv.y-1.
PubMed ID
11542925 View in PubMed
Less detail

Determination of natural and depleted uranium in urine at the ppt level: an interlaboratory analytical exercise.

https://arctichealth.org/en/permalink/ahliterature169856
Source
Health Phys. 2006 May;90(5):494-9
Publication Type
Article
Date
May-2006
Author
E A Ough
B J Lewis
W S Andrews
L G I Bennett
R G V Hancock
P A D'Agastino
Author Affiliation
Department of Chemistry and Chemical Engineering, Royal Military College of Canada, 11 General Crerar Crescent, Kingston, ON, Canada. edough@telus.net
Source
Health Phys. 2006 May;90(5):494-9
Date
May-2006
Language
English
Publication Type
Article
Keywords
Canada
Humans
Laboratories - statistics & numerical data
Microchemistry - methods
Military Personnel
Occupational Exposure - analysis
Quality Assurance, Health Care - methods
Radiation Dosage
Radioactive Waste - analysis
Radiometry - methods
Reproducibility of Results
Sensitivity and specificity
Uranium - urine
Urinalysis - methods
Abstract
An analytical exercise was initiated in order to determine those procedures with the capability to measure total uranium and uranium (238U/235U) isotopic ratios in urine samples containing >0.02 microg U kg-1 urine. A host laboratory prepared six identical sets of twelve synthetic urine samples containing total uranium in the range of 25 to 770 ng U kg-1 urine and with 238U/235U isotopic ratios ranging from 138 (100% NU) to 215 (51% DU). Sets of samples were shipped to five testing laboratories (four based in Canada and one based in Europe). Each laboratory utilized one of the following analytical techniques: sector field inductively coupled plasma mass spectrometry (ICP-SF-MS), quadrupole inductively coupled plasma mass spectrometry (ICP-Q-MS), thermal ionization mass spectrometry (TIMS), and instrumental/delayed neutron activation analysis (I/DNAA), in their analyses.
PubMed ID
16607181 View in PubMed
Less detail

Galactic and solar radiation exposure to aircrew during a solar cycle.

https://arctichealth.org/en/permalink/ahliterature187785
Source
Radiat Prot Dosimetry. 2002;102(3):207-27
Publication Type
Article
Date
2002
Author
B J Lewis
L G I Bennett
A R Green
M J McCall
B. Ellaschuk
A. Butler
M. Pierre
Author Affiliation
Royal Military College of Canada, Department of Chemistry and Chemical Engineering, Kingston, Ontario. Lewis-b@rmc.ca
Source
Radiat Prot Dosimetry. 2002;102(3):207-27
Date
2002
Language
English
Publication Type
Article
Keywords
Aerospace Medicine - methods
Aircraft
Altitude
Aviation
Background Radiation
Canada
Computer simulation
Cosmic Radiation
Humans
Models, Biological
Occupational Exposure
Radiation Dosage
Radiometry - instrumentation - methods - standards
Reproducibility of Results
Sensitivity and specificity
Solar Activity
Whole-Body Counting - methods
Abstract
An on-going investigation using a tissue-equivalent proportional counter (TEPC) has been carried out to measure the ambient dose equivalent rate of the cosmic radiation exposure of aircrew during a solar cycle. A semi-empirical model has been derived from these data to allow for the interpolation of the dose rate for any global position. The model has been extended to an altitude of up to 32 km with further measurements made on board aircraft and several balloon flights. The effects of changing solar modulation during the solar cycle are characterised by correlating the dose rate data to different solar potential models. Through integration of the dose-rate function over a great circle flight path or between given waypoints, a Predictive Code for Aircrew Radiation Exposure (PCAIRE) has been further developed for estimation of the route dose from galactic cosmic radiation exposure. This estimate is provided in units of ambient dose equivalent as well as effective dose, based on E/H x (10) scaling functions as determined from transport code calculations with LUIN and FLUKA. This experimentally based treatment has also been compared with the CARI-6 and EPCARD codes that are derived solely from theoretical transport calculations. Using TEPC measurements taken aboard the International Space Station, ground based neutron monitoring, GOES satellite data and transport code analysis, an empirical model has been further proposed for estimation of aircrew exposure during solar particle events. This model has been compared to results obtained during recent solar flare events.
PubMed ID
12430961 View in PubMed
Less detail

Modelling of radiation exposure at high altitudes during solar storms.

https://arctichealth.org/en/permalink/ahliterature149621
Source
Radiat Prot Dosimetry. 2009 Oct;136(4):311-6
Publication Type
Article
Date
Oct-2009
Author
H. Al Anid
B J Lewis
L G I Bennett
M. Takada
Author Affiliation
Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000, Kingston, ON, Canada. hani.al.anid@rmc.ca
Source
Radiat Prot Dosimetry. 2009 Oct;136(4):311-6
Date
Oct-2009
Language
English
Publication Type
Article
Keywords
Aircraft
Altitude
Aviation
Canada
Computer simulation
Cosmic Radiation
Humans
Monte Carlo Method
Occupational Exposure - analysis
Radiation Dosage
Radiation monitoring
Radiation Protection - methods
Radiometry - instrumentation - methods
Software
Solar Activity
Abstract
A transport code analysis using Monte Carlo N-Particle eXtended code, MCNPX, has been used to propagate an extrapolated particle spectrum based on satellite measurements through the atmosphere to estimate radiation exposure during solar storms at high altitudes. Neutron monitor count rate data from stations around the world were used to benchmark the model calculations during a ground-level event (GLE). A comparison was made between the model predictions and actual flight measurements taken with various types of instruments used to measure the mixed radiation field during GLE 60. A computer code has been developed to implement the model for routine analysis.
PubMed ID
19608577 View in PubMed
Less detail

9 records – page 1 of 1.